Go with Python. It's syntax is really simple and less verbose compare to others. You can use Python for basically anything like web dev, task automation, data science, data engineering, cybersecurity etc. At initial level, it's more important to get an understanding of programming fundamentals. Once you get conformable with coding in general, then you can explore other languages.
https://www.w3schools.com/ is a great resource and it's completely free, everything you need to know to build a website is on that page if you have the drive to learn it. Best of luck to you!
Here's a neat roadmap too, in case you find yourself lost on what to learn next https://roadmap.sh/frontend
Hmm, I will be honest with you, learning JS for online stores is an option, but not necessarily the easiest one. No beginner should ever attempt building an online store from scratch imo. There are too many caveats for that.
Therefore I would recommend first choosing an existing framework and then using the newfound knowledge in JS to configure this store. Many of the existing big ones are written in PHP (read wordpress), but a smart person would set the sights on an existing online store framework built on JS.
Thank you so much!
There are Telegram channels specialized in programming that help each other, especially since you will need help at the beginning